AU661909B2 - Gate latching mechanism - Google Patents

Description

r 661909 42951 DIV HKS:PFB 66 1 9 0 9 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

e Name of Applicant: LANCE MALCOLM VATER Actual Inventcr: LANCE MALCOLM VATER Address for Service: COLLISON CO.,117 King William Street, Adelaide, S.A. 5000 Invention Title: SGATE LATCHING MECHANISM This is a Divisonal of Australian Patent Application No. 18347/92 Dated 18th June 1992 The following statement is a full description of this invention, including the best method of performing it known to me: MPPP 4 2 This invention relates to a latch mechanism which is useful for the latching of a gate.

Sometimes there is a requirement for a gate to be capable of being latched closed after only a small amount of swinging movement associated with a small gate closing force, but many of the gate latches presently in use would inhibit the latching unless the gate moved with a considerable force towards its closed position.

While it is relatively easy to achieve a high gate closure force, it is desirable 1 0 that a gate latch should be operative under a small gate closing force, but it should not substantially rely upon small latching springs which can cause difficulties due to corrosion, build-up of dust or the like. Furthermore a gate closure spring loses its force as the gate approaches the closed position, so that fatigue cf tile metal of the spring can cause difficulties which may not be 1 5 apparent at the time of installation but which occur during its service.

The main object of this invention therefore is to provide a latching mechanism which can be constructed to be less likely than previous designs to cause service difficulties and which will effect a latching function when only small force is available to close the gate.

Accordingly the invention can be said to resid in a latch mechanism for releasable retention of a gate to a hollow gate post, the mechanism comprising: a subassembly including a latch bar, a pivot case being substantially U-shaped in plan and having retention means therein for retention of a hinge within the pivot case, the hinge being supported by the retention means and the hinge being located intermediate ends of the latch bar, the latch bar being free swinging about the hinge and weighted towards a closure position; control means at an upper end of the latch bar, a latch extending laterally from the lower end of the latch bar; and a striker plate on a gate, the striker plate being co-operable with the latch to deflect the latch bar away from AZI' ~its closure position upon shutting the gate but being retained by the latch bar ;upon ~S Qt '4 I. 2a upon return to its closure position; and a gate post head having surfaces of size and shape to engage the upper end of the gate post, and further retention means co-acting between the gate post head and the pivot case, the shapes and dimensions of the latch bar, latch, gate post head and pivot case being such that said subassembly can be lowered into the upper end of the gate post and suspended from said gate post head.

One of the difficulties encountered in the overall cost of a gate installation is the cost of on-site labour, and therefore, one useful feature of the invention is 10 the fact that the gate latching mechanism comprises a subassembly which includes a latch bar as aforesaid carried by a pivot case, and insertable within the top of a hollow gate post.

o •4 lp 3 Reliance solely on latching springs is avoided and the latch bar operation depends largely upon its balance of weight, and the amount of force available to retain the latch bar in position so as to securely latch a gate may be very small, and in a still further embodiment of the invention, the latch is formed from magnetic stainless material and is co-operable with a striker plate assembly which contains a magnet. This arrangement provides a very positive retention of the latch upon gate closure although only small force is required to achieve that closure.

It is already known to utilise the gate post head on a swinging upright member 1 0 of a gate, but the present heads are subject to a number of disabilities, the major one of which is that rain water can be directed by a head into the hollow of the gate post. This is obviously most undesirable because of the corrosive effects of moisture when entrapped in a hollow gate post, and in a further embodiment of the invention there is provided a gate post head which 1 5 contains a groove defined by surfaces which abut respectively inner and outer surfaces of the gate post at its upper end when the head is in position. Still further, the head may be provided with a groove in its spigot portion receiving a sealant so as to reduce the probability of moisture penetration although this is not an essential feature.

.444*4 S° 2 0 An embodiment of the invention is described hereunder with reference to and is illustrated in the accompanying drawings, in which: FIG. 1 is a partly sectioned elevational fragmentary assembly of a gate and gate post at the latching locality, FIG. 2 is a section through a gate post and latch subassembly drawn to a larger scale, and taken on line 2-2 of FIG. 1, and, C C FIG. 3 is a fragmentary sectional plan through a gate post and gate frame member, showing the latch and striker plate arrangement.

In this embodiment, the gate assembly 10 comprises a gate 11 and a gate ipost 12 both of which are only shown in a fragmentary manner, the gate post 12 comprising a latch subassembly 13 itself having a pivot case 14 which is of general U-shape in plan, the pivot case 14 having a pair of inwardly directed projections 15 intermediate the ends which support between them a bush 16, the bush 16 being rotatable about the outer surfaces of the projections 15 to form a hinge for a latch bar 17, the latch bar 17 being lanced at 18 and being arranged to rotate around outer surface of the bush 16. The sectional plane is illustrated at FIG. 1 and shows how the lancing can be effected. The upper end of the latch bar 17 has a projecting tang 19 which carries on it a knob The lower end of the latch bar 17 carries on it a latch 21 of stainless steel having magnetic properties, and positionable for height in the slot 22 near the lower end of the latch bar 17. As illustrated in FIG. 1, the latch bar 17 is weighted so that its anticlockwise moment due to the weight above the hinge effected by bush 16 exceeds its clockwise moment due to the weight below the bush 16. The degree to which it can be weighted can be modified by shaping the latch bar 17 to meet requirements, but as illustrated there is very little differential so that the latch bar 17 can be very easily deflected even though there is a minimum of effort applied to a gate in a closure direction.

1 5 As illustrated, the gate post 12 is rectangular, square in this embodiment, and is surmounted by a gate post head 24 which contains a sloping slot through which the operating hand piece 20 projects. Part way down the S-height of the gate post head 24 is an outstanding flange 26, and below that a skirt 27. The downwardly facing surface of flange 26 contains a recess 28 20 which accommodates the upper end of the gate post 12, while the skirt 27 engages the inner surfaces of the gate post 12, but the pivot case 14 is sandwiched between the two. Interengagement between the pivot case 14 and the gate post head 24 is by an upper pair of inwardly directed projections 29 which engage apertures in the skirt 27 as best seen in FIG. 2. Thus the arrangement is that a subassembly, which comprises the head 24, the pivot 14Icase 14 and the latch bar 17 assembled to the pivot case by the bush 16, can 4,S be dropped into the open top of the gate post 12. The gate post 12 however is provided with an aperture which receives a grommet 32 through which latch 1 21 moves when engaging or disengaging a striker plate 33 on the gate 11.

3 0 FIG. 3 illustrates the interaction between the latch 21 and striker plate 33.

Latch 21 in this embodiment has a circular section but is asymmetrical, its striker plate 34 being inclined at a steeper angle than the part conical plate while the striker plate 33 is a U-shaped stainless steel strip having an aperture 36 to receive the latch 21 when the gate 11 is closed, whereupon a retaining edge 37 inhibits release of the latch 21, thereby retaining the closure i mode of the gate.

to ng The metal striker plate 33 is housed in a moulding 40 which includes a sleeve ie is 41 which surrounds a gate frame member 42 and is secured thereto, and the Th r moulding 40 also has a resilient flange 43 which functions as a door stop, the ter 20. flange 43 being slightly deflected each time the gate is closed thereby eff f softening the impact upon gate closure. da the 5 in% One of the problems encountered in any gate and gate post assembly upon ba high impact which occasionally occurs is "bounce" which enables a gate to be ige b w again release. To reduce this danger, the moulding 40 also contains a pair of lat spaced retaining flanges 45 (FIG. 2) which between them retain a plate-like th permanent magnet 46, and the latch 21 is of magnetic material and tends to 10 fo adhere to plate 46 thereby reducing danger of its release upon "bounce".

There are two important features required for the gate which may be used for and example to protect a swimming pool area. It is important that the gate should be "child proof" from the outside but should be readily opened from the inside, 1 5 and to achieve this the gate post head 24 contains a key lock 49 which carries ot a on it a cam plate 50, and in the locked mode of FIG. 2, the cam plate 50 abuts a projecting portion of the upper end of the latch bar 17 to prevent its movement in an unlatching direction, but when unlocked, a spring 51 urges a ~cam plate downwardly to the downward vertical position shown in dotted linesi 4 20 at 52 so that the gate is clearly unlocked and when in that location, the latch :i ons can be readily released from the inside of the gate (the locality of the operating hand piece Dt A consideration of the above embodiment will indicate a number of can er is advantages. With the arrangement shown, there is little danger of water ch 25 entering the hollow gate post 12, and although sealants may be used between the gate post 12 and heads 24, this is generally regarded as i 1 unnecessary.

The latch bar 23 can be made from a single piece of metal which is shaped in a such a way as to reduce lateral displacement as can clearly be seen from FIG.

If i 30 2. In this respect also the pivot case 14 may be provided with inwardly direction projections 55 which flank the edges of the bar 17. The lower wings sure 56 also have the same effect. Provision may be made for stop means (not illustrated) to inhibit excessive swivelling movement of the lower end of latch y bar 17.

i

I

6 The arrangement as described above has been found by experimentation and testing to work effectively under adverse conditions. However the moment for effecting closure of the latch is nec3ssarily very small, and to further reduce danger of malfunction, there is provided a spring and stop 58 projecting inwardly from a wall of the pivot case 14 which becomes engaged by the latch bar 17 only when the knob 20 is rrved to the right (FIG. the spring 58 being clear of the latch bar otherwise but assisting in initiating return of the latch bar 17 to the closure position of latch 21, and the stop functioning to limit the extent of opening of the latch bar. This effect is achieved without the need 1 0 for latching springs.

t t i

I

Claims (2)

1. 6. a subassembly including a latch bar, a pivot case being substantially 5 sti e athU-shaped in plan and having retention means therein for retention of a hinge e ier within the pivot case, the hinge being supported by the retention means and the sti the hinge being located intermediate ends of the latch bar, the latch bar being to limitec free swinging about the hinge and weighted towards a closure position; 1 0 control means at an upper end of the latch bar, a latch extending
2. 7. laterally from the lower end of the latch bar; and a striker plate on a gate, the10 m striker plate being co-operable- with the latch to deflect the latch bar away from re its closure position upon shutting the gate but being retained by the latch bar upon return to its closure position; and a gate post head having surfaces of w and shape to engage the upper end of the gate post, and further retention lal means co-acting between the gate post head and the pivot case, the shapes and dimensions of the latch bar, latch, gate post head and pivot case being 15 8. such that said subassembly can be lowered into the upper end of the gate W ::post and suspended from said gate post head.9 2. A latch mechanism according to claim 1 wherein, the hollow gate OPP post is a hollow rectangular gate post. .:cc 3. A latch mechanism according to claim 1 or 2 wherein, the hollow 20 Ec gate posthead comprises surfaces defining a slot in a side wall of the gate t~th post, and the upper end of said latch bar comprises an operating hand piece extending outwardly through the slot. 1( 4. A latch mechanism according to any one of the preceding u wherein said retention means comprising inwardly directed projections in the pivot case, and said gate post head comprises a skirt containing apertures i eggdby sadinwardly directed projections, upper ends of said pivot case wlsbeing sadihdbetween said skirt and inner sufcsof the gaepost upon said subassembly being lowered into the upper end of the gate post. A ac ehns codn oayoeo lis2t hri i iii i.i.iMi1 r M- ii1 i '-*fj i 8 said hinge comprises a bush having bearing surfaces and operatively located Sg between said pivot case and latch bar. Ilow gate stantially 6. A latch mechanism according to any preceding claim, wherein said a hinge 5 striker plate is arranged to be carried by said gate and extend from a swinging ns and end thereof at a position to deflect said latch upon shutting the gate, said ar being striker plate having an aperture defined by edges which include a retaining nedge which releasably retains said latch. ding te, the 7. A latch mechanism according to claim 6 further comprising a vay from 1 0 moulding having walls which, upon assembly to the gate, engage and are h br retainable by a gate frame member, tch bar es of .w said striker plate being U-shaped in plan, and containing a magnet etentiwhich is engageable by a projecting end of the latch when the gate is shut, the "etention h latch being of magnetic material. ;hapes )eing 1 5 8. A latch mechanism according to claim 7, wherein said moulding Swalls include a gate stop which abuts a surface of said gate post when the gate is shut. gate gae9. A latch mechanism according to any one of claims 2 to 8, further comprising a key lock carried by the gate post head, the key lock having a 20 cam plate which can be swivelled from a first position where it is retracted to a low ate second position where it inhibits latch bar movement, and a spring biassing piece I the cam plate towards its first said position. piece t i CC r j 10. A latch mechanism according to any one of claims 2 to 9 wherein Sms, said pivot case comprises a spring/stop which is engaged by said latch bar in 2 5 upon full release of said latch from its closure position. in the res c e 11. A latch mechanism substantially as hereinbefore described with case te pos reference to and as illustrated in the accompanying drawings. te post >st. i DATED this 2nd day of June 1995 LANCE MALCOLM VATER i i By his Patent Attorneys COLLISON CO s r1 r' 1 -i i 1 )1 r ABSTRACT A latch mechanism for retaining a gate to a tubular gate post having a subassembly with a latch bar weighted to swing to a normally closed position having a latch at its lower end and a release knob at its upper end, a pivot case to which the latch bar is hinged, and a gate post head, the subassembly being inserted into the upper open end of the gate post. S 4 *4 t t